| 摘要 |
PURPOSE: A portable anglemeter is provided, which improves a reliability technology of a measurement instrument, and is adopted in an electricity amount measurement technology by a phase calculation based on a DFT(Discrete Fourier Transform) technique, and performs a real time measurement based on a microprocessor. CONSTITUTION: A port block(01) includes a power supply port, a voltage signal port and a current signal port for electrical connection between the portable anglemeter and an external device. An operation switch panel(03) includes a power switch to turn on/off a power supply of the portable anglemeter, and a measurement mode operates a switch switching two measurement modes, and a display mode switching switch switching four display modes of a display device. A power supply operation circuit(02) includes an electronic switch, an overcurrent protection circuit and a power supply display lamp. A power supply device(04) supplies a power of a level appropriate for the portable anglemeter. A CPU(Central Processing Unit)(05) has a system OS program, every kinds of measurement algorithm, every kinds of interface program and MMI(Man-Machine Interface) program, and includes a micro processor. A digital signal input circuit(07) includes a logic circuit to digitalize a contact state output signal of the measurement mode switching switch and the display mode switching switch. A voltage current detection circuit includes an auto-ranging circuit. An analog signal input circuit(09) includes a SH(Sample and Hold) and an ADC(Analog to Digital Converter) converting an output signal of the voltage current detection circuit into a digital signal. A gain control circuit(14) includes a logic circuit outputting a logic signal to the auto-ranging circuit of the voltage current detection circuit. A peripheral device includes a display device driving circuit(10), a key controller(11), a communication controller(12) and a memory device(13) and a clock and LED. And a software program analyzes test data in a clamp type current transformer and a personal computer.
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